The plasticisation model of dye diffusion: Part 8

Re‐evaluation using the Williams–Landel–Ferry equation, of exhaustion/rate of dyeing/fixation data previously reported for and acid dye, natural dye and two reactive dyes on three different types of silk substrate revealed that thermally activated dye diffusivity is governed by the thermally regulated structural relaxation times of the respective water‐saturated, water‐swollen, water‐plasticised β‐keratin macromolecule over the broad 35‐100°C range of dyeing temperatures considered. The plasticisation model of dye diffusion offers a satisfactory explanation of the temperature dependent diffusivity of each of the different classes/types of dye within the three types of water‐plasticised β ‐ keratin biopolymer: the temperature dependent exhaustion/rate of dyeing/fixation behaviour of the various dyes on silk therefore accords with Free Volume Theory .